A programmable logic device, sometimes referred to as programmable application specific integrated circuit (PASIC), field programmable gate array (FPGA), or complex programmable logic device (CPLD), is a versatile integrated circuit chip, the internal circuitry of which may be configured by an individual user to realize a user-specific circuit. To configure a programmable logic device, the user configures an on-chip interconnect structure of the programmable logic device so that selected input terminals and selected output terminals of selected on-chip circuit components are electrically connected together in such a way that the resulting circuit is the specific circuit desired by the user.
Programmable logic devices include a number of programmable logic blocks that are interconnected by a programmable routing network, sometimes referred to as an interconnect network.